Mental Decline in the Elderly After Major Surgery — Is It Avoidable?

It’s been known for over 60 years that some people aren’t quite the same after anesthesia and major surgery.

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You may have an uncle, aunt, friend, or colleague in their late 60’s or 70’s who was working as an accountant, lawyer, or engineer — some white-collar job — and then had major surgery. Thereafter, they seemingly lost their edge and had trouble going back to work.

Sadly, it’s been known for a long time (over 60 years, in fact) that some people aren’t quite the same after anesthesia and major surgery. The changes might be subtle but are evident in positions requiring significant mental focus. Past examples include an older history professor unable to return to teaching and an older practicing surgeon unable to continue doing surgery after each had his prostate glands removed.

This issue is not rare: it’s happening in 10-25% of the elderly after major surgery! In a recent 2019 study, these sorts of mental changes were noted three months after surgery in 18% of patients 60 and older who had knee replacement surgery.

Two Kinds of Mental Changes After Surgery

The Royal College of Anaesthetists has a nice patient handout about the two kinds of mental changes after surgery: postoperative delirium and postoperative cognitive dysfunction.

Postoperative delirium usually occurs 1-4 days after surgery and is marked by confusion, disorientation, erratic behavior, and anxiety. It can lead to increased hospital length of stay, increased costs, and higher mortality. The good news is it most often eventually resolves.

Postoperative cognitive dysfunction (POCD) refers to milder changes in cognition that are still present three months after surgery and may be permanent in nature. The problem with POCD is that it can greatly impact quality of life.

If a 78-year-old accountant who goes to work every day or a 73-year-old lawyer with a busy practice finds himself unable to concentrate after gall bladder removal or repair of a hip fracture, he likely will experience frustration, depression, and financial loss. There is also a cost to society when an active member of the work force no longer can perform their duties.

The anesthesia and surgical communities don’t fully understand what causes POCD or how to prevent it. Then again, 170 years after the discovery of ether and its use as an anesthetic agent, we still don’t really know much about how it works.

On a very simple level, I like to think of an hour of anesthesia and surgery as having the same effect on the brain as playing an hour of pro football (American football, not European!). Now that might not be such a big deal for a strapping 23-year-old, 190 pound linebacker, but grandpa isn’t going to come out of the game without a little confusion. And if the game (or surgery and anesthesia) lasts two or three hours, grandpa is going to be even more confused. The shorter the time grandpa stays in the “game,” the better for his head.

To carry this analogy a little further, if the anesthesia provider isn’t using the correct anesthesia techniques (such as enhanced recovery after surgery or meticulous control of blood pressure), it’s kind of like playing without a helmet. Stretching our analogy to its limits, if grandpa is not quite as sharp as he was when younger, and if he starts getting the plays wrong lots of times when they call an audible, those hours and hours of banging his head in the game are likely to cause even more damage.

We can summarize all this by saying:

  • Older patients are more susceptible to POCD.

  • The longer the surgery and anesthesia, the greater the risk of POCD.

  • Less than top-notch anesthesia and surgical care is like playing without a helmet and also increases POCD risk.

  • Older patients who already have some mental decline appear to have a more frail brain and are at even greater risk.

  • If 35 million Americans have surgery every year and one-third of them are 65 or older, we’re talking about 1 million cases of POCD. If the extra medical costs and lost wages are as small as $20,000 per patient, that’s a $20 billion cost to our society — and these are conservative numbers!

What to Do to Avoid POCD

To prevent POCD, there are simple steps you can take (not all anesthesia providers agree on these, but the steps are easy to achieve and have no downside):

  1. Since every hour of surgery is like playing an hour of pro football, the shorter the anesthesia and surgery times, the lower the risk. Even better, if you’re 75 or 80 years old and still working at a profession that requires a lot of brainpower (like a college professor), decide if the benefits of the surgery outweigh the 10-25% risk that you may have trouble going back to work. This is one arena where bigger is definitely not better!

  2. There is general agreement that low blood pressure during surgery in the elderly likely also contributes to POCD.

  3. There are many anesthetic drugs (e.g., the anti-anxiety drug midazolam, used in almost all anesthetics) that should be meticulously avoided in the elderly.

  4. Although not conclusively proven, using anesthetic techniques like spinal anesthesia (where you don’t have to go to sleep) would seem prudent.

  5. Utilizing hospitals that employ the American Society of Anesthesiologists’ perioperative surgical home model including enhanced recovery after surgery protocols in conjunction with the surgeon have the weight of evidence and opinion strongly in their favor. Remember your alphabet (PSH, ERAS) — it will go a long way!

  6. If you have to go to sleep during surgery, make sure a level of anesthesia monitor is used. The most common of these is called a BIS monitor; it’s been around for many years and although there are still naysayers that poo-poo its use, the bulk of experts believe in it. It’s cheap, simple to use, and risk-free. Not using a BIS (or similar) monitor is a pretty good way to make sure your loved one gets much harder hits in the game than needed!
    7. Unfamiliar surroundings and unfamiliar faces can also contribute to POCD. Try to get the patient home as quickly as possible, and ensure they are always surrounded by family, and bring their favorite pillow and blanket if they have to stay over. The hospital will never replace home, but a few simple touches help.
    8. Finally, and always the best advice, if you have concerns about POCD (and if you’re over 75 — even in great health), you should discuss your concerns with your anesthesia and surgical team not the morning of surgery but weeks before!

Suggested Reading

Postoperative Cognitive Dysfunction and Dementia: What We Need to know and Do

Postoperative Cognitive Dysfunction — Current Preventive Strategies